---
title: "Reference: voice.addInstructions() | Voice"
description: "Documentation for the addInstructions() method available in voice providers, which adds instructions to guide the voice model's behavior."
---

# voice.addInstructions()

The `addInstructions()` method equips a voice provider with instructions that guide the model's behavior during real-time interactions. This is particularly useful for real-time voice providers that maintain context across a conversation.

## Usage Example

```typescript
import { OpenAIRealtimeVoice } from "@mastra/voice-openai-realtime";
import { Agent } from "@mastra/core/agent";

// Initialize a real-time voice provider
const voice = new OpenAIRealtimeVoice({
  realtimeConfig: {
    model: "gpt-5.1-realtime",
    apiKey: process.env.OPENAI_API_KEY,
  },
});

// Create an agent with the voice provider
const agent = new Agent({
  name: "Customer Support Agent",
  instructions:
    "You are a helpful customer support agent for a software company.",
  model: "openai/gpt-5.1",
  voice,
});

// Add additional instructions to the voice provider
voice.addInstructions(`
  When speaking to customers:
  - Always introduce yourself as the customer support agent
  - Speak clearly and concisely
  - Ask clarifying questions when needed
  - Summarize the conversation at the end
`);

// Connect to the real-time service
await voice.connect();
```

## Parameters

<br />
<PropertiesTable
  content={[
    {
      name: "instructions",
      type: "string",
      description: "Instructions to guide the voice model's behavior",
      isOptional: false,
    },
  ]}
/>

## Return Value

This method does not return a value.

## Notes

- Instructions are most effective when they are clear, specific, and relevant to the voice interaction
- This method is primarily used with real-time voice providers that maintain conversation context
- If called on a voice provider that doesn't support instructions, it will log a warning and do nothing
- Instructions added with this method are typically combined with any instructions provided by an associated Agent
- For best results, add instructions before starting a conversation (before calling `connect()`)
- Multiple calls to `addInstructions()` may either replace or append to existing instructions, depending on the provider implementation
